Safety device for jacks.



A. H. OSTBERG.

SAFETY DEVICE FOR IACKS.

APPLICATION FILED JUNE 14, I9I5.

1,Q89,2%l q Patented Dec. 31, 1918.

2 SHEETS-SHEET I.

IHIH liven To 1-:

A. H. OSTBERG.

SAFETY DEVICE FOR JACKS.

APPLICATION FILED JUNE I4, I9I5.

1,289,241. Patented Dec. 31, 1918.

2 SHEET EET 2.

ALBERT E. OSTBERG, 0F AUROEA,-ILLINOES.

SAFETY DEVICE FOR JACKS.

Specification of Letters Batent.

Application filed June 14, 1915. Serial No. 34,030.

To all whom it may concern:

Be it known that I, ALBERT H. Os'renno, a citizen of the United States,residing at Aurora, in the county of Kane and State of Illinois, haveinvented certain new and useful Improvements in Safety Devices forJacks, of which the following is a specification.

This invention relates to a safety stop for jacks, or the like, and thepurpose of the invention is to provide an improvement in acks wherebythey may be operated with increased safety and efilciency.

1n jacks such as are commonly employed for lifting purposes, thestandard wh1ch supports the object to 'be lifted is shdably mounted in aframe and projected upwardly or downwardly by suitable operatingmechanism. The principal object of this invention is to provide meansfor limiting the movement of the standard in the frame. further objectis to provide means for l miting the upward movement of the ack, wherebythe projection thereof from its seat and other disastrous results areprevented. Another object is to provide a detachable safety stop. Stillanother object is to pro vide a safety stop which will limit themovement of the standard in one direction, while freely permittingmovement thereof in the reverse direction.

These and other objects of the invention will appear more fully in thefollowing specification, taken in connection with the accompanyingdrawings, in which one embodiment andone application of the inventionare illustrated.

In the drawings Figure 1 is avertical section through a jack providedwith my improvement, takenv on the line 11 of Fig. 3.

Fig. 2 is a side elevation of an improved key for preventing rotation ofthe standard of the jack. v

Fig. 3 is a horizontal sectional view taken on a plane passing throughthe line 3-3 of Fig. 1.

' Fig.4 is a fragmentary side elevation of the jack, showing a portionthereof in sec,- tion on the line 4-4 of Fig. 3.

Fig. 5 is a perspective view of one of the stops or detent members; and

Fig. 6 is a side elevation of a detent guide and retaining member.

In the drawings the jack in which my improvements are embodied is shown'as comprisinga frame or body 10, the lower portion of which is enlargedto form a housing for suitable operating mechanism, and the upperportion 11 of which is in theform of a vertically-extending sleevehaving a cylindrical bore therethrough which is closely fitted bytheslidably mounted standard 12. This standard is provided with anenlarged head 13 at its upper extremity, which is adapted to engage theobject tobe lifted, and when said standard is in its lowermost positionthe enlarged head is adapted to seat upon an annular-flange 14, formedat the upper extremity of the portion 11 of the frame. The standard 12is provided on its outer side with a vertically-extending groove orkey-way 15, which extends downwardly from the enlarged-head 13 to thelower extremity of the standard. A key 16 closely fits the key-way 15 inthe standard, and has formed integrally therewith a stud .17 whichextends through and closely fits an aperture 18 in the sleve 11 to beengaged by a nut 19, which coacts with a boss 20 formed in the outerside of the sleeve, whereby the key is held in fixed position withrespect to the body or frame. It will be understood that the key isplaced in position with respect to the frame before the standard 12 islowered into position within the sleeve 11. By means of the constructionjust described, the standard is permitted to slide vertically, but isprevented from rotating with respect to the frame.

The standard 12 is further provided with an axial bore, the upper partof which is enlarged, as shown at 21, and the lower portion of which'isprovided with screw threads adapted to engage a screw-threaded drivingspindle 22., This spindle is provided. at the lower extremity of thethreaded portion thereof, with an integrally-formed collar '23, whichseats upon a lbevel gear 24 mounted upon the cylindrical bearing portion25 of The bevel gear 2 1 is secured Patented Dec. 3t, 1918..

with the axis of the spindle'22. A collar 30 seats on the lower wall ofthis chamber and rotatably engages the portion 25 of the spindle. Thecap member is provided, upwardly of the collar 30, with an annularflange 31, which serves to retain the balls 32 against radial movementin an outward direction. These balls seat upon the collar,

and are prevented from moving inwardly by the loosely mounted sleeve 33,which rests upon the collar 30. These parts are so proportioned that theu per portions of the balls 32 extend beyon the upper surfaces of thecap member 27 and sleeve 33, and seated upon the balls is a secondcollar 35," which also closely engages the portion 25 of the spindle,and WlllOh forms a seat for the lower plane surface of the bevel gear24.

The bevel gear 24 and spindle 22 are actuated by a bevel pinion 36,carried by a horizontally-operated shaft 37 having a projecting portion38 adapted to be engaged by a suitable operating means or source ofpower. The standard 12 is cut away at 12 to provide clearance for thebevel pinion 36. The horizontal shaft 37 is journaled in a hub 39,carried by a cap member 40, which closes the opening in thelaterally-extending projection 41 of the. frame 10, being securedthereto by suitable pins '42 and the bolts 43 and nuts 44. It will beapparent that uponrotation of the horizontal operating shaft 37, thebevel gear 24 and spindle 22 will be actuated, and thereby move thestandard 12 a upwardly or downwardly in the frame, ac-

cording to the direction of rotation of the shaft 37. As the standard 12moves upwardly in the frame, the downward thrust thereof will bereceived by the thrust-bearing previously described.

It will be apparent that unless suitable preventive means be provided,the con tinued operation of the shaft 37 in the proper direction, andthe corresponding rotation of the spindle 22, would project the standard12 upwardly out of the sleeve 11 of the frame, which would probablyresult in breakage of parts of the jack, injury to the object beingliftedthereby, or other serious consequences.

For the purpose of preventing such result,

I have provided an improved safety stop which automatically limits .theupward travel of the standard. The sleeve portion 11 of the body orframe is provided, ad-v jacent the annular flange 14, with twodiametrica1ly opposite bosses 45, which are provided with aliningapertures 46 therethrough, adapted to be closely fitted by the stopguide and retaining members 47. Theseguide members are provided withannular flanges 48, which closely engage the outer plane surfaces 45 ofthe bosses 45, and the inner extremities of the members 47 sleeve 11.Studs 52 engage the lugs 50 andbosses 51, and thereby secure the guidemembers 47 in place with respect to the frame. Each guide member isprovided with a rectangular radially extendin v chamber or guideway 54,which is closely fitted by a slidably mounted detent or stop member 55.A coil spring 56 is mounted in each of the chambers 54 outwardly of thedetent 55, and serves normally to project the same inwardly into thebore of the sleeve 11.

The outer cylindrical surface of the standard 12 serves normally toprevent the detent members 55 from be1ng projected inwardly, but whenthe standard has reached the desired upper limit of its travel, the

detent members are automatically projected inwardly to engage theparallel transverse grooves 58, which are provided in the standardadjacent its lower extremity. These grooves are provided with lowerradiallyextending surfaces 59, which preferably lie in the same radialplane, and with upper outwardly inclined surfaces 60, which are adaptedto coact with the correspondingly inclined surfaces 61 formed on thedetent members 55. Itwill be apparent that when the standard 12 hasmoved upwardl until the grooves 58 register with the gui e-ways 54, thedetent members 55 will be automatically projected inwardly to engagesaid grooves and thereby prevent further upward movement of thestandard, owing to the engagement of the stops 55 with the surfaces 59.The guide members 47 are formed to fit closely the apertures 46, so

'that the thrusts received from'the standard are transmitted directly tothe frame, in-

stead of throughthe studs 52, which serve as fastening means. Upon thereverse operation of the spindle 22, however, the inclined surface 60will coact with the inclined surfaces 61 on the detent members, therebyforcing the detent members outwardly in the guide-ways 54 against 'theably applied for limiting the downward movement of the standard. It willbe observed that the detent members are diametrically opposed, and theyare preferably arranged toengage the standard simultaneously, so that.the further upward movement of the standard will be resisted atdiametrically opposite points, thus preventing twisting and bendingstrains upon the standard and spindle, or other parts of the device. Thedetent members are preferably so located as to lie in a plane at rightangles to a radial plane passing through the key-way 15, and it will beobserved that the detenting devices and the key 16 are so arranged asnot to interfere with the handle 10* on the frame, which serves as ameans for transporting the jack, or with the cut away portion 12 of thestandard.

A great advantage of my improved stop is that it operates automaticallyto limit the upward movement of the standard, or to permit the reversemovement of the standard thereafter, and it will be apparent that if anyof the parts of the stop become worn or impaired by use, the guidemembers 47 may be readily removed by detaching the studs 52, after whichthe worn or impaired parts can be easily repaired or replaced.

Another important advantage of my improved stop is that it may bereadily applied to jacks already constructed without great or costlyalterations thereof, by providing the spindle of the jack with suitabledepressions or grooves and the walls of the framewith suitable aperturesto be engaged by the guide members.

Although I have shown and described a particular embodiment of theinvention, and have explained its application in connection with aparticular form of jack, it will be understood that my improved stop maybe applied to various forms of jacks, or the like, and may itselfpartake of widely different forms and arrangements of parts withoutdeparting from the scope of my invention as defined in the appendedclaims.

I claim 1. The combination with the movable standard of a jack, of aspring pressed detent for limiting the upward movement thereof, adetachable guiding housing for said detent, a cylindrical plugat one endof said housing, a flange intermediate the ends of said housing, and asecuring lug depending from said flange.

2. The combination with the movable standard and frame of a jack, of adetachable stop housing and guide member comprising a cylindrical plugadapted to fit an aperture in said frame adjacent said movable standard,said plug having an arcuate surface on one end thereof concentric withthe adjacent surface of said movable standard, an annular flangeextending around the other end of said plug and adapted to engage theouter wall of said frame to maintain said plug in position in saidaperture with its arcuate shaped end spaced slightly outwardly from saidstandard and from the inner wall of said frame, a lug depending fromsaid flange, securing means for engaging said lug, and a recess in saidhousing extending on both sides of said flange.

'3. The combination with the movable standard and frame of a jack, of adetachable stop housing and guide -member comprising a plug adapted tofit an aperture in said frame adjacent said movable standard, said plughaving an arcuate surface on one end thereof concentric with theadjacent surface of said movable standard, an annular flange extendingaround the other end of said plug and adapted to engage the outer wallof said frame to maintain said plug in position in said aperture, a lugdepending from said flange, securing means for engaging said lug, and arecess in said housing extending on both sides of said flange.

4. A device of the class described, comprising a housing provided with anipple at one end, a flange adjacent the inner end of said nipple, arecess in said housing extending on both sides of said flange, a springand a detent in said housing, and a securing lug depending from saidflange and pro vided with an aperture for the reception of fasteningmeans, all of said elements constituting a unitary structure bodilyattachable to and detachable from the frame of a jack.

In testimony whereof, I have subscribed my name.

ALBERT H. OSTBERG. Witnesses:

J. A. CARNEY, E. J. BABBITT.

